Celtic maintained their ten-point lead at the top of the Scottish Premier League with a stylish away win against Dundee United.

The champions, who seem to have come through their sticky patch, could have been ahead as early as the second minute when John Hartson burst into the penalty area and unleashed a shot that was turned aside by a one-handed save from Paul Gallacher.

But the Wales striker was taking full advantage of his place in the starting line-up and a minute later Celtic were ahead. Jackie McNamara played the ball through to Hartson and he left Gallacher helpless as he fired his shot into the bottom left-hand corner of the net.

He could have grabbed a second after eight minutes from a free-kick by Stilian Petrov. The Bulgarian flighted the ball into the path of Bobo Balde and the defender nodded on to Hartson, but he failed to connect from just a few yards out.

Celtic had the ball in the net again after 10 minutes, when Alan Thompson's through-ball was met by Hartson, but referee John Rowbotham ruled that the Celtic striker had pushed David Partridge and the effort was disallowed.

Dundee United's first real chance came a few seconds later, but Steven Thompson's long-range drive was well blocked by Rab Douglas in the Celtic goal.

Celtic's continuous pressure paid off once again and they doubled their lead after 27 minutes. Henrik Larsson and McNamara exchanged passes before McNamara squared the ball across goal to Petrov, who tapped in from three yards.

Only the heroics of goalkeeper Gallacher prevented Celtic from piling further misery on the home side. He produced a fine save to deny Larsson after 28 minutes and was called into action again a minute later.

This time the Swede connected awkwardly with a Thompson corner, the ball bounced off his body and only another fine save from Gallacher stopped it from tumbling over the line.

The home side, whose scoring chances had been few and far between, tried to put Celtic under pressure five minutes before the break, when Jim Paterson's pass found Thompson in the area, but the danger was cleared before the United forward could connect.

Celtic continued to dominate in the second half and they sealed their win with a stunning free-kick by Thompson and a fourth by the prolific Larsson.